[sql] Refactor to remove use of const_cast<>.

The comments in these cases used incorrect reasoning for why the
const_cast<> was safe.  Whether the SQL statements modify the database
is irrelevant.  Add an internal helper to allow them to correctly
accomplish things in a const situation.

BUG=none
TEST=none


Review URL: https://chromiumcodereview.appspot.com/10736042

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148031 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 10 insertions, 1 deletions

diff --git a/sql/connection.h b/sql/connection.h
index fba0326..e5c9469 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -338,6 +338,7 @@ class SQL_EXPORT Connection {
    public:
     // Default constructor initializes to an invalid statement.
     StatementRef();
+    explicit StatementRef(sqlite3_stmt* stmt);
     StatementRef(Connection* connection, sqlite3_stmt* stmt);
 
     // When true, the statement can be used.
@@ -387,6 +388,14 @@ class SQL_EXPORT Connection {
   bool ExecuteWithTimeout(const char* sql, base::TimeDelta ms_timeout)
       WARN_UNUSED_RESULT;
 
+  // Internal helper for const functions.  Like GetUniqueStatement(),
+  // except the statement is not entered into open_statements_,
+  // allowing this function to be const.  Open statements can block
+  // closing the database, so only use in cases where the last ref is
+  // released before close could be called (which should always be the
+  // case for const functions).
+  scoped_refptr<StatementRef> GetUntrackedStatement(const char* sql) const;
+
   // The actual sqlite database. Will be NULL before Init has been called or if
   // Init resulted in an error.
   sqlite3* db_;